Silica fillers are used in rubber composites to modify their dynamic-mechanical properties. Three fillers are used: a commercial filler of precipitated silica type Vulkasil- S and two fillers obtained by its treatment in different ways: thermally and hydrothermally. The purpose is not only to obtain higher hysteresis of the composite at low temperatures and lower hysteresis at elevated temperature (which is optimal for good tire performance), but to understand the reasons of such changes in elastomer materials behavior and also possibilities to increase the corresponding trends. Both modified fillers exhibited required trends in comparison with the original commercial one. More detailed analyses of their dynamical behavior indicate interdependence between of filler particle size, morphology of particle aggregates and ratio of elastic to loss moduli, influencing all together the dynamic properties of products.